Many investigations have hitherto been made on syntheses of benzodiazepine derivatives for the purpose of developing an agonist for the central nervous system acting upon the benzodiazepine receptor (a psychotropic drug).
It was recently reported that some of the benzodiazepine derivatives exhibit antagonism for the CCK-A (cholecystokinin-A) receptor and the CCK-B (cholecystokinin-B) receptor. It was also reported that the compounds exhibiting a higher degree of antagonism for the CCK-B receptor than that for the CCK-A receptor serve to depress the gastric-acid secretion caused by the stimulus of pentagastrin (Eur. J. Pharmacol., 162, 273-280, 1989).